Collating and binding systems for saddle stitchers are, of course, well known in the printing industry for mass producing booklets, magazines, catalogues, advertising brochures and the like. Typically, one or more sharply folded and generally pre-printed blanks or signatures are sequentially fed by a number of spaced signature feeders. The signatures are delivered such that the folded margins or spines of the signatures come to rest upon a collating conveyor line or chain which travels past the signature feeders. The conveyor gathers the signatures, one on top of the other, and moves them through one or more on-line printing stations to a stitching or binding station. The assembled signatures then are usually diverted to a trimming station and further led to a labelling station where mailing labels which are pre-printed or printed on-line are affixed.
Prior art systems of this type contemplate the computer controlled production of various editions of books or catalogues of internal and external signatures containing individually tailored information or customized printing on selected signatures without expensive alterations. This flexibility remains important in satisfying the demands of a particular market or geographical destination. For instance, it may be desirable to offer certain customers or subscribers various features or selected advertising depending upon their locale, income or occupation. Likewise, it may be relevant to customize products or services contingent upon a customer's previous buying history. In addition, flexibility of printing external or cover signatures is important to the sender in meeting postal regulations and qualifying for substantial postage discounts.
One system which discloses the customized printing of signatures is shown in U.S. Pat. No. 4,121,818 issued on Oct. 24, 1978, to Reilly et al. In this arrangement, a first printer adjacent the collating conveyor is located on line between the signature feeders while a second printer is located at the end of the conveyor for printing mailing labels on the gathered books. This system is limiting in the sense that only the outside pages of internal signatures of a book may be printed as they travel upon the conveyor. In addition, the Reilly et al system is particularly inflexible in applying printing only in a direction parallel to the spine or fold of the internal signature. This results in the customized information running opposite to the normal left to right reading of the book and forces the reader to turn the book or reader's head in order to digest the tailored message.
A similar drawback is present in another such system, disclosed in U.S. Pat. No. 4,395,031 issued on July 26, 1983, to Gruber et al. According to this system, a printer cooperates with a plate-like member to open an internal signature selected from the collating conveyor and provide printing on both the inside and outside of a signature. As in other bindery systems, the personalization of internal signatures occurs adjacent the conveyor only downstream of all the signature feeders just before the signatures are bound. This creates the same problematic result in printing disposition as discussed above.
To aid in fully appreciating the problem which develops from the on-line customized printing of internal signatures, a discussion of further details of a collating and binding system which is thoroughly conventional in the printing industry is provided. Such systems must be capable of efficiently producing, in high volume and at high speeds, books of various numbers of pages formed of paper stock of different sizes, weights and finishes. The paper stock is stored in a supply stack in each of the signature feeders which are aligned in rows of multi-unit sections, also known in the art as boxes or pockets. Each of these signature feeders extracts a single folded signature from their supply stack, opens the signature and delivers it, with its fold in draped fashion upon a collating conveyor chain which travels directly in front of the aligned signature feeders. Such feeders are well known and are disclosed in U.S. Pat. Nos. 2,251,943 issued Aug. 12, 1941 to Kleineberg.
Because of the nature in which signatures are handled and gathered, the prior art has generally been known to provide customized printing of internal signatures by placing printing devices adjacent the collating conveyor chain such that printing is applied in a direction paralleling the chain and the fold of the signature. In short, this approach has not provided an easily readable or flexible personalization in existing printing systems dealing with the collation of internal signatures.
One system which provides customized printing in a direction transverse to the spine or fold of the signature is described in German Patent No. 3,421,208 issued Dec. 12, 1985 to Wenzke. In this device, a conveyor belt transports a signature under an addressing device for customized printing before the signature is delivered to the collating and binding line. The problem with this design, however, is that there is no control over the position or registration of the signature on the conveyor belt. This, in turn, may cause crooked and/or inaccurate personalization as well as possible jamming as the customized but unregistered signature is delivered to the collating and binding line. The probability of these problems escalates with the increasingly higher operating speeds of these systems.
From the foregoing, it can be seen that various attempts have been made by the prior art to upgrade the customized printing capability of collating and binding systems. However, there remains a need in this well-developed art for a system which offers more flexibility and control in the provision of personalized information and overall processing of signatures.